Merge pull request #9923 from danmcclain/psql-concurrent-indexes

Adds support for concurrent indexing in PostgreSQL adapter

9 files changed, 86 insertions, 35 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 16460ec36d..a37147af2b 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -3,6 +3,18 @@
 *   PostgreSQL geometric type point is supported by ActiveRecord. Fixes #7324.
 
     *Martin Schuerrer*
+ 
+*   Add suport for concurrent indexing in PostgreSQL adapter via the
+    `algorithm: :concurrently` option
+
+        add_index(:people, :last_name, algorithm: :concurrently)
+
+    Also adds support for MySQL index algorithms (`COPY`, `INPLACE`,
+    `DEFAULT`) via the `algorithm: :copy` option
+
+        add_index(:people, :last_name, algorithm: :copy) # or :inplace/:default
+
+    *Dan McClain*
 
 *   Add an `add_index` override in Postgresql adapter and MySQL adapter
     to allow custom index type support. Fixes #6101.
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 26cacbde37..d5ae4058ed 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -752,12 +752,20 @@ module ActiveRecord
           index_name   = index_name(table_name, column: column_names)
 
           if Hash === options # legacy support, since this param was a string
-            options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using)
+            options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using, :algorithm)
 
             index_type = options[:unique] ? "UNIQUE" : ""
             index_name = options[:name].to_s if options.key?(:name)
             max_index_length = options.fetch(:internal, false) ? index_name_length : allowed_index_name_length
 
+            if index_algorithms.key?(options[:algorithm])
+              algorithm = index_algorithms[options[:algorithm]]
+            elsif options[:algorithm].present?
+              raise ArgumentError.new("Algorithm must be one of the following: #{index_algorithms.keys.map(&:inspect).join(', ')}")
+            end
+
+            using = "USING #{options[:using]}" if options[:using].present?
+
             if supports_partial_index?
               index_options = options[:where] ? " WHERE #{options[:where]}" : ""
             end
@@ -772,6 +780,7 @@ module ActiveRecord
 
             index_type = options
             max_index_length = allowed_index_name_length
+            algorithm = using = nil
           end
 
           if index_name.length > max_index_length
@@ -782,7 +791,7 @@ module ActiveRecord
           end
           index_columns = quoted_columns_for_index(column_names, options).join(", ")
 
-          [index_name, index_type, index_columns, index_options]
+          [index_name, index_type, index_columns, index_options, algorithm, using]
         end
 
         def index_name_for_remove(table_name, options = {})
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 0f4ab68b61..1915c444ef 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -282,6 +282,13 @@ module ActiveRecord
         []
       end
 
+      # A list of index algorithms, to be filled by adapters that
+      # support them. MySQL and PostgreSQL has support for them right
+      # now.
+      def index_algorithms
+        {}
+      end
+
       # QUOTING ==================================================
 
       # Returns a bind substitution value given a +column+ and list of current
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 71f5c8fd29..ff3e9acfac 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -208,6 +208,10 @@ module ActiveRecord
         NATIVE_DATABASE_TYPES
       end
 
+      def index_algorithms
+        { default: 'ALGORITHM = DEFAULT', copy: 'ALGORITHM = COPY', inplace: 'ALGORITHM = INPLACE' }
+      end
+
       # HELPER METHODS ===========================================
 
       # The two drivers have slightly different ways of yielding hashes of results, so
@@ -506,12 +510,8 @@ module ActiveRecord
       end
 
       def add_index(table_name, column_name, options = {}) #:nodoc:
-        if options.is_a?(Hash) && options[:using]
-          index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
-          execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} USING #{options[:using]} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options}"
-        else
-          super
-        end
+        index_name, index_type, index_columns, index_options, index_algorithm, index_using = add_index_options(table_name, column_name, options)
+        execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options} #{index_algorithm}"
       end
 
       # Maps logical Rails types to MySQL-specific data types.
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 688bf1774b..0e1afbae8d 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -410,12 +410,8 @@ module ActiveRecord
         end
 
         def add_index(table_name, column_name, options = {}) #:nodoc:
-          if options.is_a?(Hash) && options[:using]
-            index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
-            execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} USING #{options[:using]} (#{index_columns})#{index_options}"
-          else
-             super
-          end
+          index_name, index_type, index_columns, index_options, index_algorithm, index_using = add_index_options(table_name, column_name, options)
+          execute "CREATE #{index_type} INDEX #{index_algorithm} #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} #{index_using} (#{index_columns})#{index_options}"
         end
 
         def remove_index!(table_name, index_name) #:nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index d26b676335..46e41e6b48 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -433,6 +433,10 @@ module ActiveRecord
         true
       end
 
+      def index_algorithms
+        { concurrently: 'CONCURRENTLY' }
+      end
+
       class StatementPool < ConnectionAdapters::StatementPool
         def initialize(connection, max)
           super
diff --git a/activerecord/test/cases/adapters/mysql/active_schema_test.rb b/activerecord/test/cases/adapters/mysql/active_schema_test.rb
index 568fd45888..9050ae3fe3 100644
--- a/activerecord/test/cases/adapters/mysql/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql/active_schema_test.rb
@@ -21,30 +21,37 @@ class ActiveSchemaTest < ActiveRecord::TestCase
     ActiveRecord::ConnectionAdapters::MysqlAdapter.send(:define_method, :index_name_exists?) do |*|
       false
     end
-    expected = "CREATE  INDEX `index_people_on_last_name` ON `people` (`last_name`)"
+    expected = "CREATE  INDEX `index_people_on_last_name`  ON `people` (`last_name`) "
     assert_equal expected, add_index(:people, :last_name, :length => nil)
 
-    expected = "CREATE  INDEX `index_people_on_last_name` ON `people` (`last_name`(10))"
+    expected = "CREATE  INDEX `index_people_on_last_name`  ON `people` (`last_name`(10)) "
     assert_equal expected, add_index(:people, :last_name, :length => 10)
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` ON `people` (`last_name`(15), `first_name`(15))"
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name`  ON `people` (`last_name`(15), `first_name`(15)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => 15)
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` ON `people` (`last_name`(15), `first_name`)"
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name`  ON `people` (`last_name`(15), `first_name`) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => {:last_name => 15})
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` ON `people` (`last_name`(15), `first_name`(10))"
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name`  ON `people` (`last_name`(15), `first_name`(10)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => {:last_name => 15, :first_name => 10})
 
     %w(btree hash).each do |type|
-      expected = "CREATE  INDEX `index_people_on_last_name` USING #{type} ON `people` (`last_name`)"
+      expected = "CREATE  INDEX `index_people_on_last_name` USING #{type} ON `people` (`last_name`) "
       assert_equal expected, add_index(:people, :last_name, :using => type)
     end
 
-    expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10))"
+    expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10)) "
     assert_equal expected, add_index(:people, :last_name, :length => 10, :using => :btree)
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` USING btree ON `people` (`last_name`(15), `first_name`(15))"
+    expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10)) ALGORITHM = COPY"
+    assert_equal expected, add_index(:people, :last_name, :length => 10, using: :btree, algorithm: :copy)
+
+    assert_raise ArgumentError do
+      add_index(:people, :last_name, algorithm: :coyp)
+    end
+
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` USING btree ON `people` (`last_name`(15), `first_name`(15)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => 15, :using => :btree)
 
     ActiveRecord::ConnectionAdapters::MysqlAdapter.send(:remove_method, :index_name_exists?)
diff --git a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
index 273ef978bf..48d63aeef5 100644
--- a/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/active_schema_test.rb
@@ -21,30 +21,37 @@ class ActiveSchemaTest < ActiveRecord::TestCase
     ActiveRecord::ConnectionAdapters::Mysql2Adapter.send(:define_method, :index_name_exists?) do |*|
       false
     end
-    expected = "CREATE  INDEX `index_people_on_last_name` ON `people` (`last_name`)"
+    expected = "CREATE  INDEX `index_people_on_last_name`  ON `people` (`last_name`) "
     assert_equal expected, add_index(:people, :last_name, :length => nil)
 
-    expected = "CREATE  INDEX `index_people_on_last_name` ON `people` (`last_name`(10))"
+    expected = "CREATE  INDEX `index_people_on_last_name`  ON `people` (`last_name`(10)) "
     assert_equal expected, add_index(:people, :last_name, :length => 10)
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` ON `people` (`last_name`(15), `first_name`(15))"
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name`  ON `people` (`last_name`(15), `first_name`(15)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => 15)
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` ON `people` (`last_name`(15), `first_name`)"
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name`  ON `people` (`last_name`(15), `first_name`) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => {:last_name => 15})
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` ON `people` (`last_name`(15), `first_name`(10))"
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name`  ON `people` (`last_name`(15), `first_name`(10)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => {:last_name => 15, :first_name => 10})
 
     %w(btree hash).each do |type|
-      expected = "CREATE  INDEX `index_people_on_last_name` USING #{type} ON `people` (`last_name`)"
+      expected = "CREATE  INDEX `index_people_on_last_name` USING #{type} ON `people` (`last_name`) "
       assert_equal expected, add_index(:people, :last_name, :using => type)
     end
 
-    expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10))"
+    expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10)) "
     assert_equal expected, add_index(:people, :last_name, :length => 10, :using => :btree)
 
-    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` USING btree ON `people` (`last_name`(15), `first_name`(15))"
+    expected = "CREATE  INDEX `index_people_on_last_name` USING btree ON `people` (`last_name`(10)) ALGORITHM = COPY"
+    assert_equal expected, add_index(:people, :last_name, :length => 10, using: :btree, algorithm: :copy)
+
+    assert_raise ArgumentError do
+      add_index(:people, :last_name, algorithm: :coyp)
+    end
+
+    expected = "CREATE  INDEX `index_people_on_last_name_and_first_name` USING btree ON `people` (`last_name`(15), `first_name`(15)) "
     assert_equal expected, add_index(:people, [:last_name, :first_name], :length => 15, :using => :btree)
 
     ActiveRecord::ConnectionAdapters::Mysql2Adapter.send(:remove_method, :index_name_exists?)
diff --git a/activerecord/test/cases/adapters/postgresql/active_schema_test.rb b/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
index ac36d0e835..16329689c0 100644
--- a/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/active_schema_test.rb
@@ -29,18 +29,27 @@ class PostgresqlActiveSchemaTest < ActiveRecord::TestCase
       false
     end
 
-    expected = %(CREATE UNIQUE INDEX "index_people_on_last_name" ON "people" ("last_name") WHERE state = 'active')
+    expected = %(CREATE UNIQUE INDEX  "index_people_on_last_name" ON "people"  ("last_name") WHERE state = 'active')
     assert_equal expected, add_index(:people, :last_name, :unique => true, :where => "state = 'active'")
 
+    expected = %(CREATE  INDEX CONCURRENTLY "index_people_on_last_name" ON "people"  ("last_name"))
+    assert_equal expected, add_index(:people, :last_name, algorithm: :concurrently)
+
     %w(gin gist hash btree).each do |type|
-      expected = %(CREATE  INDEX "index_people_on_last_name" ON "people" USING #{type} ("last_name"))
-      assert_equal expected, add_index(:people, :last_name, :using => type)
+      expected = %(CREATE  INDEX  "index_people_on_last_name" ON "people" USING #{type} ("last_name"))
+      assert_equal expected, add_index(:people, :last_name, using: type)
+
+      expected = %(CREATE  INDEX CONCURRENTLY "index_people_on_last_name" ON "people" USING #{type} ("last_name"))
+      assert_equal expected, add_index(:people, :last_name, using: type, algorithm: :concurrently)
     end
 
-    expected = %(CREATE UNIQUE INDEX "index_people_on_last_name" ON "people" USING gist ("last_name"))
+    assert_raise ArgumentError do
+      add_index(:people, :last_name, algorithm: :copy)
+    end
+    expected = %(CREATE UNIQUE INDEX  "index_people_on_last_name" ON "people" USING gist ("last_name"))
     assert_equal expected, add_index(:people, :last_name, :unique => true, :using => :gist)
 
-    expected = %(CREATE UNIQUE INDEX "index_people_on_last_name" ON "people" USING gist ("last_name") WHERE state = 'active')
+    expected = %(CREATE UNIQUE INDEX  "index_people_on_last_name" ON "people" USING gist ("last_name") WHERE state = 'active')
     assert_equal expected, add_index(:people, :last_name, :unique => true, :where => "state = 'active'", :using => :gist)
 
     ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.send(:remove_method, :index_name_exists?)